Valve



Feb.1s,194`1. E KRIESE Em y 2,232,538

I VALVE Filed Jan. 13, 1939 I r'wer'wtor-*st Erwin Krese, Hubert'Konclorfer,

Patented Feb. 1s, 1941 UNITED STATES PATENT OFFICE VALVE YorkApplication January 13,1939, serial No. 250,858 In Germany January 2-2,1938 1 Claim.

This invention relates to pressure fluid distributing valves and moreparticularly to valves which are adapted to be `operated to the openedposition by an externally applied force and are automatically reclosedafter a predetermined time delay.

Pressure fluid control valves arranged for automatic reclosing with timedelay characteristics generally embody m-ore or less complicatedmechanisms which are subject to faulty operation. Aside from highinitial cost, the necessity for frequent repair and replacement of partshave rendered the valves of known designs unsuitable where reliabilityand uninterrupted service is of prime importance.

It is an `object of this invention to provide a new and 'improvedcontrol valve -of the type referred to which has relatively few movableparts, is simple in design and reliable in operation.

It is a further object of this invention to provide a new and improvedcontrol valve which is manually operable to the opened position,maintained in the lopened position by an unbalance 'J or forces exertedby the flow of fluid therethrough, and automatically reclosed after apredetermined time delay.

In the illustrated embodiments of this invention, a valve is providedwith a disk which is biased to the closed position. An expansiblebellows arrangement is operatively associated with the disk which whenthe disk is moved to the opened position effects an unbalance of fluidpressure acting upon the disk whereby it is held opened against thebiasing means. Pressure iluid is admitted into the bellows chamberthrough an adjustable orice from the discharge side of the valve wherebythe pressure acting upon the disk is gradually balanced allowing thedisk to close under the force of the biasing means.

For a consideration of what we believe to be novel and our invention,attention is directed to the following description and the claimappended thereto taken in connection with the accompanying drawing. v

In thedrawing Fig. 1 illustrates a typical pressure iluid operatingsystem embodying a control valve of the type herein described; Fig. 2 isa cross-sectional elevation through one modification of a valveaccording to this invention; while Fig. 3 illustrates a secondmodification.

In certain pressure uid operating systems, such as for operating heavyduty circuit breakers, a valve is provided for controlling the ow ofoperating fluid, such as compressed air, to the actuating servo motoruntil it is moved to a predetermined position. Upon reaching suchposition asupon the completion of the circuit breaker closing operation,it is desirable that the valve should automatically cut off the supplyof pressure fluid from the servo motor so that it may be `immediatelyreturned to the inoperative position in readiness for a second operatingcycle.

In a typical pressure fluid `operating system shown in Fig. 1, I0 is auid pressure actuating means or servo motor of a well-known formhavingan operating rod II yextending therefrom for performing any suitableoperation, such as the closing of an electric circuit breaker (notshown.) Pressure fluid, such as compressed air, is supplied to the servomotor IIJ through lthe inlet connection I2 having a valve I3 therein forcontrolling the supply of pressure fluid fro-m a suitable source (notshown) through the conduit I4. A valve I5 arranged in the dischargeconduit I6 controls the discharge of pressure fluid from the cylinder ofthe servo motor. Assuming first that the servo motor I0 is in theinoperative position and it is desired to energize the motor, the ValveI5 is rst closed and the push button I'Iof the valve I3 is depressedwhereby pressure iluid from the source is admitted to the cylinder ofthe servo. motor. When the piston of the servo motor has reached itslimit of travel and pressure builds up therein substantially equal tothe supply pressure, the valve I3 is automatically -operated to theclosed position, the servo motor I0 being maintained in the operatedcondition by the volume of uid within its cylinder. The servo motor maybe tripped to the inoperative position by any suitable means arrangedfor opening the discharge valve I5 in response to any predeterminedcondition.

The uid pressure supply controlling valve I3, according to ourinvention, is illustrated in detail in one form in Fig. 2` in which thevalve housing I8 is shown having inlet and outlet passages I9 and 20respectively. A valve disk 2| is arranged Within the inlet chamber andbiased to the seating position by means of the spring 22 'arrangedbetween the inlet side of the disk and the lower housing Wall. One endof a flexible bellows member 23 is secured to the inlet side o'f thevalve `disk 2l substantially around the periphery thereof and the otherend tothe lower housing wall forming a fluid-tight chamber 24 having amean diameter substantially equal to the seating diameter of the valvedisk. Since the valve inlet side of the disk is protected from the fluidpressure of the source, the disk is normally retained in the seatedposition primarily by the biasing force of spring 22. A passage 25 incommunication with the outlet chamber of the valve through therestricted opening 26 extends around the valve housing `and furthercommunicates with the chamber 24 within the bellows member throughopenings 21. By means of the adjusting valve 28 arranged in therestricted openingv 2B, the rate of pressure fluid flo-w into thechamber 25 may be regulated to attain the desired time delaycharacteristic for the valve closing operation. The housing or casingvhas a projection disposed within the chamber 24 to center the spring 22and to act as a stop limiting opening movement of the valve 2| andthereby also to prevent excessive compression ofy the bellows 23. Thevalve disk is adapted to be actuated to the opened position by means ofthe push rod 2| which extends through the housing and is secured to theoutlet side of the disk. In the operation ofthe valve when the disk 2|is unseated and pressure fluid admitted to the servo motor, the pressureacting on the outlet side of the valve disk will maintain it openagainst'the bias of the spring 22. Pressure fluid will flow through therestricted opening 26 and through the openings 21 into the interior ofthe bellows chamber 24, the rate of ow being relatively slow, however,due to the relatively low pressure obtaining in the valve outlet passage20. As soon as the piston of the serv-o motor I0 reaches its imit oftravel, the pressure at the discharge side of the valve will becomesubstantially equal t0 the pressure of the supply and the rate of fluidflow through the passage 26 into the bellows chamber 24 will increase.Upon the equalization of the fluid pressure forces acting upon theopposite sides of the disk, the biasing spring 22 will actuate the valvedisk to the closed position where it will remain until the nextoperation.

If in the event that the valve l5 controlling the discharge from thecylinder of the servo motor I0 was not first closed before the button l1was depressed, as an indication that some phase of the system was not inreadiness for the energization ofthe motor I0, the pressure fluid woulddischarge through conduit I6 with no effect as regards the operation ofthe servo motor I0. Under such conditions the uid owing through thepassage 26 will within a predetermined length of time, as determined bythe setting of the valve 28, build up the pressure within the bellowschamber 24 substantially equal to the pressure acting upon the oppositeside of the disk whereupon the valve disk will be moved to the closedposition preventing the continuous passage of operating fluidtherethrough. This length of time, however, is such that during thenormal operation of the system, the valve will remain open at leastuntil the piston of the servo motor has had full opportunity to reachits limit of travel.

In Fig. 3 is shown a second modification of the invention in which avalve housing 38, having inlet and outlet passages 3l and32,respectively, is provided with a valve disk 33 secured to the end ofthe push rod 34 extending through the discharge chamber 35. The valvedisk is biased to the closed position by the spring 36 arranged betweena disk 31 secured to the push rod 34 and a wall 38 extending across thedischarge chamber 35. A ilexible bellows 39 having one end sealed to theperiphery of the disk 31 and the other end to the wall 38 forms asubstantially duid-tight chamber 40 except for the passage 4l throughthe wall 38 communicating with the exhaust chamber 35. An adjustablevalve 42 controls the rate of pressure fluid ow through the opening 4linto the bellows chamber. 1t will Y be noted that openings 43 areprovided in the wall 38 allowing free flow from the main valve openingto the outlet 32 around the sides of the bellows member 39.

The operation of the valve according to the second modication issubstantially similar to `that previously described.- When the valvedisk is actuated to the open position by the depression of the push rodagainst the bias of the spring 31, the disk 33 is maintained in theopened positionby virtue of the unbalance of the fluid pressure actingupon the valve disk resulting from the low pressure obtaining within thebellows chamber 40. The pressure acting upon the exposed, or outer,surface of the disk 31 exerts a force upon the push rod 34 in oppositionto the force acting upon the inlet side of the valve disk 33 and in thesame direction as the force acting upon the opposite side of the valvedisk. After a predetermined time limit when the pressure within thebellows chamber 48 builds up substantially equal to the pressureexteriorly thereof, the disk 33 will be closed by action of the spring31.

Having described the principle of operation of our invention togetherwith the apparatus which we now consider to represent the bestembodiment thereof, we desire to have it understood that the apparatusshown is only illustrative and that the invention may be carried out byother means.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

A pressure iiuid controlling valve comprising a housing having inlet andoutlet passages, a valve disk arranged between said passages and adaptedto be actuated to the opened position in the direction of said inletpassage, a flexible bellows member having a mean diameter substantiallyequal to the seating diameter of said disk secured at one end to theperiphery of said disk at the valve inlet yside thereof, the other endof said bellows member being sealed to an adjacent wall o-f said valvehousing, a spring arranged within said bellows member between saidhousing wall and said disk for biasing said disk to the closed position,the casing having a projection disposed within the chamber to center thespring and to limit opening movement of the valve disk, a push rodextending through said valve housing and secured to the outlet side ofsaid valve disk whereby said disk may be operated to the openedposition, a passage formed by the housing and communicating with thevalve outlet passage and with the interior of said bellows member, andmeans for regulating the rate of fluid flow from said valve outletpassage into said bellows member.

ERW'IN KRIESE. HUBERT KORNDRFER.

